In many computer networks, the growth of virtual private networks (VPNs) and their widespread usage has accelerated greatly. In particular, more nodes are being interconnected through VPNs, e.g., more customers and corresponding customer edge devices (CEs) are interconnected with more provider edge devices (PEs, or “edge routers” generally), which may be interconnected with more provider devices (Ps, or “backbone/core routers”), etc., as will be understood by those skilled in the art. In addition, the number of services available to the larger number of nodes participating in VPNs has also increased. For example, certain “high touch” services, such as firewalls or other deep packet inspection services, may be available to a plurality of customer networks upon entrance to the service provider's network, e.g., at the PEs.
Ultimately, the combination of the increase in nodes and services in VPNs has created various issues with scalability. One such scaling concern is the amount of routing information (“state”) maintained at the edge routers (PEs), as currently all of such information is kept at the edge routers. The larger number of customers (and CEs), VPNs, backbone/core routers (Ps), etc. results in a substantially large amount of routing information to maintain. Often, this large amount of routing information is burdensome for edge routers, especially where a majority of edge routers is only interconnected to a small number (e.g., one or two) of backbone routers. Moreover, each of the services available to the VPNs may also be computationally demanding (e.g., certain high touch services). For this reason, it may be a further burden to the edge routers to perform such services for the large number of attached customer networks (e.g., VPNs), particularly where other devices (e.g., more specialized routers) may be better-suited to perform such services, such as where those devices may have greater processing/computing power, larger memory, specialized functionality, etc., that is not available at the edge routers.